System and method for spread spectrum communication

Abstract

A spreading code generating apparatus carries out M-sequence multiplication and zero value addition of generated orthogonal codes to obtain channel identification codes, and then carries out inverse Fourier transform of the channel identification codes to generate spreading codes and inverse spreading codes. A transmitting apparatus and a receiving apparatus store the spreading codes and the inverse spreading codes generated by the spreading code generating apparatus, respectively, and use a single code respectively selected from the stored codes to carry out spread spectrum communication.

1 - 8 . (canceled) 
     
     
         9 . A method for transmitting a binary code using a Frequency Division Multiplexing (FDM), comprising:
 outputting one PN binary code chosen from a plurality of PN binary codes;   modulating a plurality of subcarriers in a band, one-by-one, by binary element values, respectively, of the one PN binary code;   multiplexing the subcarriers having been modulated to obtain a transmission signal; and   transmitting the signal in an IFT (Inverse Fourier Transform) symbol time duration.   
     
     
         10 . The method according to  claim 9 , wherein, in said modulating step, subcarriers in one group or plural groups of successive subcarriers in frequency domain are modulated by the binary element values, respectively, of the one PN binary code. 
     
     
         11 . The method according to  claim 10 , wherein, in said modulating step, the successive subcarriers are modulated such that while preserving an unused frequency subcarrier between the groups of successive carriers. 
     
     
         12 . The method according to  claim 9 , wherein the PN binary code is used for identifying a transmitting apparatus in a system operated by the FDM. 
     
     
         13 . An apparatus for transmitting a binary code using a Frequency Division Multiplexing (FDM), said apparatus comprising:
 a processor that executes instructions; and   a memory device having said instructions stored thereon, wherein   said instructions are issued for:   outputting one PN binary code chosen from a plurality of PN binary codes;   modulating a plurality of subcarriers in a band, one-by-one, by binary element values, respectively, of the one PN binary code;   multiplexing the subcarriers having been modulated to obtain a transmission signal; and   transmitting the signal in an IFT (Inverse Fourier Transform) symbol time duration.